The present invention concerns the design of a cam for a composite camshaft for controlling the valves in internal-combustion engine and featuring the characteristics recited in the preamble to claim 1.
Cams and camshaft of this genus are described in German 4 121 951 C2. The core of the shaft differs in thickness along its length, and, to facilitate sliding the cam over it, the cam is provided with a cavity that tapers out like a funnel at least part-way along at least one side. The outside diameter of the opening into the cavity is at least as long as the ridges or webs that constitute the thicker sections of the core. The conical expansion extends at least ⅕ of the thickness of the cam and has an apical angle of approximately 20xc2x7.
This design has drawbacks. First, in spite of the funnel-shaped expansion, considerable force is required to mount the cams. Furthermore, it is difficult to keep the cams precisely centered on the core.
The object of the present invention is a cam with a bore that has a funnel-shaped core-insertion section ensuring that the cam will rest more securely against the core and remain more precisely centered.
This object is attained in accordance with the present invention by the characteristics recited in the body of claim 1. Advantageous further and more advance embodiments are addressed in the subsidiary claims, 2 through 8.